Leaflet Mobility Research Articles

Entire mitral reconstruction with porcine extracellular matrix in an acute porcine model

ObjectiveThe objective of our study was to investigate the feasibility of reconstructing the entire mitral valvular and subvalvular apparatus in pigs using a modified tube graft design made of 2-ply small intestinal submucosa extracellular matrix. MethodsThe reconstructions were performed in an acute 80-kg porcine model with 8 pigs, each acting as its own control. A modified tube graft was designed from a sheet of 2-ply small intestinal submucosa extracellular matrix. Before and after mitral valve reconstruction, echocardiography was used to assess mitral regurgitation, left ventricular outflow tract obstruction due to systolic anterior motion, mitral stenosis, leaflet mobility, and leaflet geometry. ResultsThe reconstructed mitral valves were fully functional without any observable echocardiographic signs of regurgitation. We did not observe any left ventricular outflow tract obstruction due to systolic anterior motion nor any mitral valve stenosis, despite a diminished septal-lateral distance after reconstruction. The reconstruction had a reduced tenting area, a reduced coaptation length (9.6 ± 1.7 mm vs 7.9 ± 1.0 mm, P = .010, diff = −1.7 mm, 95% confidence interval, −3.1 to −0.4 mm), and atrial bending of both leaflets. ConclusionsIn this acute porcine study, entire mitral valvular and subvalvular apparatus reconstruction using a modified tube graft design made from 2-ply small intestinal submucosal extracellular matrix was feasible. The 2-ply small intestinal submucosa extracellular matrix could withstand the pressure exerted by the left ventricle without any signs of tearing or rupture. These promising results warrant further assessment of both the annular geometry and the long-term durability.

Histochemical characterization and connective fiber distribution of the cardiac outflow tract of pirarucu, Arapaima gigas (Schinz, 1822) (Osteoglossiformes, Arapaimidae)

The cardiac outflow tract (OFT) in teleosts is composed of a proximal short conus arteriosus and a distal well-developed bulbus arteriosus located between the ventricle and ventral aorta. The role of these anatomical components includes structural connections, prevention of blood backflow and blood pressure control, which are related to their histological and histochemical compositions. A previous study in the heart of the Amazonian species Arapaima gigas reported an unusual OFT arrangement among teleosts that has been found only in members of Osteoglossiformes so far. Thus, considering the wide structural variability of the teleostean OFT, the present study focuses on identifying glycosaminoglycans types and describing the distribution of collagen, elastic and reticular fibers in the conus arteriosus, conal valves, and bulbus arteriosus of A. gigas. Hearts from A. gigas between 327 and 4040 g weight were used. Collagen fibers were concentrated in regions that were regularly exposed to stress, as elastic fibers showed a broad distribution in all anatomical segments. Several fibrous connections between the conal valve leaflets and the conus arteriosus were observed, possibly acting as the primary connection form. The functions of the connective fibers in the valve leaflets and the bulbus are supported by an extracellular matrix rich in non-sulfated glycosaminoglycans. The complex reticular fiber network in the compact myocardium of the conus and the smooth muscle of the bulbus wall suggests a relevant role in support contraction of both muscle types, and in attachment and mobility of the conal valve leaflets.

Interscallop indentation closure as an adjunctive technique in mitral valve repair for degenerative mitral valve disease.

Interscallop indentation closure is a useful adjunctive technique which presents several different effects in repairing degenerative mitral regurgitation. However, there are some concerns that it might reduce mitral valve area by restricting the posterior leaflet mobility. We aim to assess postoperative echocardiographic findings after mitral valve repair using this technique. Between January 2009 and December 2015, 897 patients underwent mitral valve repair for degenerative mitral regurgitation at our institutions. We reviewed 98 patients in which we used indentation closure technique, and we analyzed operative and echocardiographic data. Ring annuloplasty and concomitant repair techniques such as leaflet resection and neochordal placement were used in all patients. Specific purposes of indentation closure included gap closure (n = 57), prolapse repair (n = 11), leaflet redundancy repair (n = 16), and leaflet deficiency repair (n = 12). Eleven patients had double indentation closure. Postoperative pre-discharge echocardiography showed no moderate or greater residual mitral regurgitation, mean transmitral pressure gradient of 3.4 ± 1.4mmHg, and mitral valve area of 2.7 ± 0.7cm2. Follow-up echocardiography performed at 43.7 ± 23.9months after surgery showed six cases (6.4%) with recurrent moderate or greater mitral regurgitation, mean transmitral pressure gradient of 3.3 ± 1.3mmHg, and mitral valve area of 2.5 ± 0.6cm2. Interscallop indentation closure is a simple and effective adjunctive technique which can be used for several different purposes. It achieves excellent control of mitral regurgitation with preserved mitral valve area when it is used in addition to standard mitral valve repair techniques in selected cases.

Impact of BASILICA on Sinus and Neo-Sinus Hemodynamics after Valve-in-Valve with and without Coronary Flow

Background/purposeThis study aims at evaluating the impact of BASILICA on neo-sinus and sinus hemodynamics with and without coronary flow. Leaflet thrombosis after valve-in-valve (ViV) may compromise not only leaflet mobility but also affect valve durability and performance. Methods/materialsIn a 23 mm transparent surgical aortic valve model, a 23 mm Edwards SAPIEN 3 and a 26 mm Medtronic Evolut were deployed before and after leaflet laceration, in models with and without coronary flow. Neo-sinus and sinus hemodynamics were evaluated in the aortic position of a pulse duplicator and particle image velocimetry was performed in order to quantify sinus flow hemodynamics along with sinus and neo-sinus washout. ResultsBASILICA-type leaflet laceration procedure led to (a) an increase in the velocities in the sinus and the neo-sinus by 50% for Evolut ViV with and without coronary flow, 70% for non-coronary SAPIEN 3 ViV and 10% for coronary SAPIEN 3 ViV, and (b) an improvement in overall washout up to 2 cycles in the neo-sinus and 0.5 cycles in the sinus. ConclusionsA BASILICA-type leaflet laceration approach may improve sinus and neo-sinus hemodynamics through decreasing flow stasis and enabling less confined blood flow. BASILICA confers coronary sinus flow patterns to the non-coronary sinus.

Impact of transcatheter aortic valve replacement on hemodynamic status in patients with aortic stenosis and mitral stenosis: Doppler echocardiographic study

BackgroundMitral stenosis (MS) is often concomitant with aortic stenosis (AS). However, little is known about the functional status following transcatheter aortic valve replacement (TAVR) alone in patients with severe AS and MS and the impact of TAVR for AS on MS hemodynamics. MethodsWe enrolled 11 patients (age 83.6±4.7 years, eight women) with severe AS and MS who underwent TAVR. We compared New York Heart Association (NYHA) functional class and mean transmitral pressure gradient (MPG), mitral valve area (MVA), and stroke volume (SV) measured by transthoracic Doppler echocardiography between baseline and after TAVR. We also examined the calcification of the mitral annulus and mitral leaflet opening. ResultsNYHA functional class improved after TAVR in all 11 patients. As SV increased after TAVR (52±12mL to 63±18mL, p=0.041), MPG decreased and MVA increased (6.9±3.8mmHg to 5.1±2.5mmHg, p=0.011 for MPG and 1.12±0.25cm2 to 1.49±0.43cm2, p=0.035 for MVA). However, MPG increased in one patient in whom calcification extended into the entire anterior mitral leaflet (AML) and AML mobility was severely reduced. ConclusionsNYHA functional class and hemodynamic status of MS improved after TAVR in patients with severe AS and MS. TAVR might provide therapeutic efficacy for selected symptomatic severe AS patients with MS.

Repair of bileaflet prolapse in Barlow syndrome: The 4-chord technique.

Barlow syndrome is a form of degenerative mitral valve (MV) disease found in a subset of patients with bileaflet prolapse. The hallmark of Barlow's disease includes excessive and billowing leaflet tissue caused by myxomatous tissue proliferation, elongated chordae, and pronounced annular dilatation. Surgical repair of patients with Barlow's disease is challenging due to the extent of the leaflet and annular abnormalities. Several techniques have been described to repair Barlow's MV including currently popular "non-resectional" approaches. Repair with neochordae has been associated with excellent results and includes the advantage of preserved leaflet mobility and a large surface of coaptation. We describe a simple approach to the use of neochordae to repair bileaflet prolapse in patients with Barlow syndrome and avoid systolic anterior motion.

Modeling mitral valve stenosis: A parametric study on the stenosis severity level

New computational techniques providing more accurate representation of human heart pathologies could help uncovering relevant physical phenomena and improve the outcome of medical therapies. In this framework, the present work describes an efficient computational model for the evaluation of the ventricular flow alteration in presence of mitral valve stenosis. The model is based on the direct numerical simulation of the Navier–Stokes equations two-way coupled with a structural solver for the left ventricle and mitral valve dynamics. The presence of mitral valve stenosis is mimicked by a single-parameter constraint acting on the kinematics of the mitral leaflets.Four different degrees of mitral valve stenosis are considered focusing on the hemodynamic alterations occurring in pathologic conditions. The mitral jet, generated during diastole, is seen to shrink and strengthen when the stenosis gets more severe. As a consequence, the kinetic energy of the flow, the tissues shear stresses, the transvalvular pressure drop and mitral regurgitation increase. It results that, as the stenosis severity level increases, the geometric and effective orifice areas decrease up to 50% with respect the normal case due to the reduced leaflets mobility and stronger blood acceleration during the diastolic phase. The modified intraventricular hemodynamics is also related to a stronger pressure gradient that, for severe stenosis, can be more than ten times larger than the healthy valve case. These computational results are fully consistent with the available clinical literature and open the way to the virtual assessment of surgical procedures and to the evaluation of prosthetic devices.

Severely Impaired Leaflet Mobility of the Tricuspid Valve in an Elderly Woman.

Severely Impaired Leaflet Mobility of the Tricuspid Valve in an Elderly Woman.

THE CONE RECONSTRUCTION OF EBSTEIN ANOMALY: A CASE REPORT

Ebstein anomaly is a rare congenital defect in which origins of variably deformedposterior and septal leaflets of tricuspid valve are displaced downwards into rightventricle(failure of delamination, with characteristic sail-like anterior leaflet.Rotational displacement of tricuspid valve divides the right ventricle into proximal(atrialized) and distal (ventricularized) portions. Due to marked dilation of trueannulus and right ventricle, ebstein valves are usually regurgitant. Out ofnumerous reapir techniques, Da Silva's Cone reconstruction is different in that itis closest to anatomical repair in which there is mobilization of anterior andposterior tricuspid leaflets from their anomalous attachments in the rightventricle, with clockwise rotation of the free edge and sutured to the septal borderof anterior leaflet. The basic principle of this repair is to create a cone with its tipfixed at the right ventricular apex and the base sutured to the true tricuspid valveannulus level. We present a case of Ebstein anomaly in which Cone repair wasdone with uneventful recovery.

Usefulness of the Echocardiographic Calcium Score to Refine Risk of Major Adverse Cardiovascular Events Beyond the Traditional Framingham Risk Score

Echocardiographic calcifications are associated with major adverse cardiovascular events (MACE). A recently described semiquantitative Global Cardiac Calcium Score (GCCS) has been associated with mortality and stroke, with increasing scores associated with increasing risk. This score assigns points for calcium in the aortic root and valve, mitral valve and annulus, and submitral apparatus, with additional points for restricted leaflet mobility. We tested the hypothesis that the GCCS could improve prediction of MACE beyond traditional risk scores. This was a retrospective study of 216 subjects from a general echocardiography database (mean age 59 ± 15; 51% male). Follow-up was 3.8 ± 1.7 years. The Framingham Risk Score (FRS) and Pooled Cohort Equations (PCE) were applied to each patient. Mean GCCS was 3.2 ± 2. In the total cohort, GCCS predicted MACE (myocardial infarction, stroke, all-cause mortality), even after adjusting for FRS (odd ratio 1.19, p = 0.03). There were 106 subjects (49%) in the low-risk FRS group, 71 (33%) in the intermediate-risk group, and 39 (18%) in the high-risk group. GCCS ≥3 was associated with increased MACE (vs <3) in the low-risk group (p = 0.03), while GCCS <3 was associated with decreased MACE (vs ≥3) in the high-risk group (p = 0.04). When applied to the PCE risk estimate (dichotomized at <7.5% vs ≥7.5%) the GCCS similarly refined risk prediction. In conclusion, the semiquantitative GCCS appears to be a marker of additional unaccounted risk factors; it is easily applied and can further stratify risk of MACE beyond traditional FRS or PCE estimates.

Invited Commentary

Invited Commentary

Acute Thrombosis of Bioprosthetic Mitral Valve Secondary to Peri-Operative VA-ECMO; The Dangers of Flow Stasis in the Left Atrium

Case report Veno-Arterial (VA) ECMO has been used to help patients recover from cardiogenic shock. VA-ECMO can complicate recovery due to the increase in afterload and decreased flow through the left sided chambers. We present a case of acute bioprosthetic mitral valve (MV) thrombosis in a patient who developed peri-operative cardiogenic shock. A 63 year-old male admitted for acute systolic heart failure found to have coronary artery disease and valvular heart disease underwent MV replacement, tricuspid valve repair and three vessel coronary artery bypass grafting. He developed intraoperative mediastinal bleeding requiring fresh frozen plasma, cryoprecipitate, and factor VII. The patient was unable to be weaned off cardiopulmonary bypass secondary to right ventricular failure. The patient remained centrally cannulated for VA-ECMO and had placement of a femoral intra-aortic balloon pump. The patient was transferred to the ICU in shock and on multiple vasopressors. Due to ongoing mediastinal bleeding, initiation of systemic anticoagulation was delayed by 48 hours. The intraoperative transesophageal echocardiogram (TEE) initially demonstrated a normally functioning bioprosthetic MV. The final intraoperative TEE images following conversion to VA-ECMO showed a poorly opening bioprosthetic MV, Image 1 . A TEE on postoperative day (POD) 2 demonstrated abnormal mobility of the bioprosthetic MV leaflets, left appendage thrombus and smoke-like echogenicity in the left atrium, Image 2 . On POD 5, a TEE demonstrated mean MV gradient of 22 mmHg and worsening of MV mobility secondary to thrombus, Image 3 . Because of concern for MV thrombosis, the patient was taken to the catheterization lab for placement of LV catheter to confirm MV stenosis. A thrombolytic agent was infused via a pulmonary artery (PA) catheter in order to attempt lysis of the MV thrombus. On POD 9, the PA systolic pressures reduced from 50 mmHg to 30 mmHg and the VA-ECMO flow requirements were reduced from 5 to 3.5 Liters per minute. Despite this small improvement in hemodynamics his overall clinical status did not improve. Ultimately the family decided to withdraw care. A post-mortem examination confirmed MV stenosis secondary to thrombosis of the valve extending into the left atrial appendage. Patients in cardiogenic shock who are placed on VA-ECMO are extremely sensitive to the high afterload created by retrograde arterial flow. Our patient developed severe thrombotic MV stenosis secondary to left atrial circulatory stasis when VA-ECMO was initiated. Maintaining adequate left sided flow is crucial to reduce the risk of thrombosis.

Mitral annuloplasty ring with selective flexibility for septal-lateral contraction and remodelling properties.

To develop and evaluate a novel mitral annuloplasty ring with selective flexibility for septal-lateral contraction and rigidity for septal-lateral dilatation in an acute porcine model. The novel mitral annuloplasty ring was designed with slits in the luminal posterior segment and annular lateral segments. The slits were designed to allow inward motion during contraction and to block outward motion during dilation. The novel mitral annuloplasty ring was tested in vitro with a dedicated mechanical test bench, followed by in vivo characterization, using sonomicrometry and echocardiography for annular and leaflet geometry, in an acute porcine model. From the in vitro characterization, we verified that the ring could easily contract (0.7 mm/N) in the septal-lateral dimension, while dilatation was restrained (0.4 mm/N). In vivo characterization showed a cyclic range of 2.8 ± 0.0 mm for septal-lateral contraction. A novel saddle-shaped remodelling mitral annuloplasty ring was developed with selective flexibility for septal-lateral contraction and rigidity for septal-lateral dilatation. The advantages of this specific ring is that it re-establishes the coaptation plane, ensures leaflet mobility and septal-lateral flexibility and at the same time improves tissue adaptation and thereby decreases the risk of ring dehiscence and redilatation of the mitral annulus. This concept may prove beneficial for patients with ischaemic mitral valve regurgitation or degenerative valve disease.

Extracting Thickness Profiles of Anterior Mitral Leaflets in Echocardiography Videos.

Rheumatic heart disease is the serious consequence of repeated episodes of acute rheumatic fever. It is the major cause of heart valve damage resulting in morbidity and mortality. Its early detection is considered vital to control the disease's progression. The key manifestations that are visible in the early stages of this disease are changes in the thickness, shape and mobility of the mitral valve leaflets. Echocardiography based screening is sensitive enough to identify these changes in early stages of the disease. In this work, an automatic approach is proposed to measure, quantify and analyze the thickness of the anterior mitral leaflet, in an echocardiographic video. The shape of the anterior mitral leaflet is simplified via morphological skeletonization and spline modelling to get the central line of the leaflet. To analyze the overall thickness from the tip to its base, the anterior mitral leaflet is divided into four quartiles. In ach quartile the thickness is measured as the length of the line segment resulting from the intersection of the contour with the normal direction of the central point of each quartile. Finally, the thickness is analyzed by measuring the variance per quartile, divided by leaflet position (open, straight and closed). The comparison between the normal and pathological leaflets are also presented, exhibiting statistical significant differences in all quartiles, especially near the tip of the leaflet.

The influence of His bundle pacing on tricuspid valve functioning using three-dimensional echocardiography

Key Teaching Points • In most patients, the His bundle pacing (HBP) lead is positioned on the atrial side of the His bundle; in others, it is positioned in the tricuspid valve or on the ventricular side of the His bundle. • Echocardiography showed no worsening of tricuspid regurgitation severity in any patient with a permanent HBP, even in those whose leads were located on or under the tricuspid valve. • The HBP lead tip can be positioned in a commissural position in the right ventricle without impinging on leaflet mobility.

Mitral valve posterior leaflet reconstruction using extracellular matrix: an acute porcine study.

To investigate mitral valve posterior leaflet and subvalvular reconstruction using a 2-ply small intestinal submucosal extracellular matrix sheet. Mitral valve posterior leaflet and subvalvular reconstruction was characterized in an acute 80-kg porcine model with 7 pigs acting as their own controls. The characterization was based on pressure catheter measurements of pressure differences to identify mitral regurgitation, stenosis and systolic anterior motion. Furthermore, echocardiography was used for the evaluation of leaflet mobility and geometry, whereas sonomicrometry was used to describe annular and subvalvular geometry. The reconstructed mitral valve was fully functional without any signs of regurgitation (peak left atrial pressure for baseline and reconstruction 12 ± 2 mmHg vs 11 ± 2 mmHg, P = 0.550), mitral valve stenosis (mean pressure difference across the mitral valve 4.8 ± 2.3 mmHg vs 4.1 ± 2.3 mmHg, P = 0.589) or systolic anterior motion. The echocardiographic characterization revealed septal-lateral downsizing, reduced tenting area, increased coaptation length (6.0 ± 0.6 mm vs 8.7 ± 2.3 mm, P = 0.002) and an atrial bend of the reconstructed posterior leaflet. A ballooning effect of the patch material was present at the posterior annular segment. Mitral valve posterior leaflet and subvalvular reconstruction using a 2-ply small intestinal submucosal extracellular matrix sheet as patch material was possible in an acute porcine model. The reconstructed mitral valve was fully functional without signs of mitral valve stenosis, valve regurgitation, stenosis or systolic anterior motion. The ballooning appearance of the patch material might, however, constitute an altered leaflet stress distribution in this area.

Comparison of Cormatrix® porcine extracellular matrix and pericardial patch augmentation for tricuspid valve leaflet reconstruction - A singlecenter experience.

Background and aim: Leaflet augmentation to treat restrictive mitral leaflet motion in type IIIB mitral regurgitation is well-known. Leaflet augmentation of the tricuspid valve is less well described. The aim of this retrospective study was to assess short- and long-term valve function and patient outcome in all patients receiving tricuspid valve leaflet augmentation with either Cormatrix or bovine/autologous pericardium in our institution from 2007 to 2016. Materials and methods: NYHA class, diagnosis, type of surgery and health state were found through chart review. Echocardiography exams before surgery, 1 month after, 6 months after, and latest exam were analyzed regarding biventricular function, valve function, leaflet mobility and –thickness. Results: In eight patients; Cormatrix (n=4), bovine pericardium (n=3), and autologous pericardium (n=1) were used for 7 anterior leaflet extensions and 1 septal leaflet extension. Follow-up ranged from 6 to 132 months. Three patients had died, two in the Cormatrix group, and one in the pericardial group. Over time, coaptation length (12 ± 5 mm vs. 8 ± 3 mm, p=0.03) decreased significantly in the Cormatrix group, while none of the other parameters differed significantly. A tendency towards reduced leaflet mobility and thickening of the pericardialextended leaflets were seen over time. Conclusion: Cormatrix and pericardium as patch material for tricuspid leaflet extension are comparable regarding valve performance and durability of the repair in this study, though resorption of Cormatrix material seems to take place leading to decreasing coaptation height. This is a sign of tissue remodelling. Leaflet mobility was reduced in the pericardial repair group and may likely be related to thickening of pericardial patch material that occurred over time.

Comparison of Cormatrix® porcine extracellular matrix and pericardial patch augmentation for tricuspid valve leaflet reconstruction - A singlecenter experience.

Background and aim: Leaflet augmentation to treat restrictive mitral leaflet motion in type IIIB mitral regurgitation is well-known. Leaflet augmentation of the tricuspid valve is less well described. The aim of this retrospective study was to assess short- and long-term valve function and patient outcome in all patients receiving tricuspid valve leaflet augmentation with either Cormatrix or bovine/autologous pericardium in our institution from 2007 to 2016. Materials and methods: NYHA class, diagnosis, type of surgery and health state were found through chart review. Echocardiography exams before surgery, 1 month after, 6 months after, and latest exam were analyzed regarding biventricular function, valve function, leaflet mobility and –thickness. Results: In eight patients; Cormatrix (n=4), bovine pericardium (n=3), and autologous pericardium (n=1) were used for 7 anterior leaflet extensions and 1 septal leaflet extension. Follow-up ranged from 6 to 132 months. Three patients had died, two in the Cormatrix group, and one in the pericardial group. Over time, coaptation length (12 ± 5 mm vs. 8 ± 3 mm, p=0.03) decreased significantly in the Cormatrix group, while none of the other parameters differed significantly. A tendency towards reduced leaflet mobility and thickening of the pericardialextended leaflets were seen over time. Conclusion: Cormatrix and pericardium as patch material for tricuspid leaflet extension are comparable regarding valve performance and durability of the repair in this study, though resorption of Cormatrix material seems to take place leading to decreasing coaptation height. This is a sign of tissue remodelling. Leaflet mobility was reduced in the pericardial repair group and may likely be related to thickening of pericardial patch material that occurred over time.

Outcome of tricuspid valve surgery in the presence of permanent pacemaker

ObjectivesGiven the paucity of available literature, we sought to evaluate the mechanisms of tricuspid regurgitation and the outcomes of tricuspid valve surgery in the presence of permanent pacemakers. MethodsWe retrospectively reviewed the records of 622 adult patients who underwent tricuspid valve surgery in the presence of permanent pacemakers between January 1993 and December 2013. Those with prosthetic tricuspid valve or tricuspid valve endocarditis and those undergoing concomitant heart transplant were excluded (n = 23). Patients were divided into 2 etiologic groups: pacemaker-associated tricuspid regurgitation (n = 349, 58%) and pacemaker-induced tricuspid regurgitation (n = 249, 42%). One patient was not categorized, because permanent pacemaker involvement was unknown. ResultsMean age was 69.5 ± 12.0 years; 312 patients (52%) were female. In pacemaker-associated tricuspid regurgitation, the most common cause was functional (n = 304, 87%). The most common mechanism leading to pacemaker-induced tricuspid regurgitation was restricted leaflet mobility (n = 101, 41%), followed by adherent leaflet to the leads (n = 93, 37%), leaflet perforation (n = 30, 12%), scarring of leaflets (n = 19, 8%), and chordal entrapment (n = 18, 7%). The most common leaflet involved was septal leaflet (n = 182, 73%). Tricuspid valve repair (n = 215, 62%) was higher in the pacemaker-associated tricuspid regurgitation group. In multivariable analysis, pacemaker-induced tricuspid regurgitation was found to be protective with improved survival (hazard ratio [HR], 0.79; 95% confidence interval [CI], 0.68-0.98). Other independent risk factors of mortality included tricuspid valve replacement (HR, 1.50; 95% CI, 1.20-1.87), nonelective surgery (HR, 1.66; 95% CI, 1.33-2.08), diabetes (HR, 1.37; 95% CI, 1.09-1.73), severe tricuspid regurgitation (HR, 1.42; 95% CI, 1.04-1.95), and older age when there was a concomitant aortic valve surgery (HR, 1.44; 95% CI, 1.15-1.79). ConclusionsSeveral mechanisms lead to pacemaker-induced tricuspid regurgitation. Pacemaker-induced tricuspid regurgitation when compared with pacemaker-associated tricuspid regurgitation carries a better prognosis with improved survival.

Neochordoplasty versus leaflet resection for ruptured mitral chordae treatment: Virtual mitral valve repair

Degenerative mitral valve (MV) disease involving mitral prolapse is one of the most prevalent MV pathologies. Quadrangular leaflet resection and neochordoplasty demonstrate excellent clinical outcomes for the treatment of posterior leaflet prolapse. We evaluated the functional and biomechanical characteristics of a virtual pathologic MV model suffering from chordal rupture, performed virtual neochordoplasty and quadrangular leaflet resection, and compared the two post-repair MV functions. The pre-repair MV demonstrated severe posterior leaflet prolapse due to the ruptured P2 chordae and excessive stress concentration. Both repair techniques revealed reduced leaflet prolapse, decreased stress concentration, and restored leaflet coaptation. While neochordoplasty demonstrated further improved leaflet coaptation and superior posterior leaflet mobility, leaflet resection showed more uniform leaflet stress distributions. Virtual MV repair simulation has the ability to predict and quantitate biomechanical and functional improvement following MV repair. This strategy has the potential to help determine the most effective repair technique to restore MV function.